Diagnostic Value Of Intraluminal Stent Enhancement In Estimating Coronary In-Stent Restenosis

Objective: In-stent restenosis (ISR) diagnosis is among the most serious complications of patients undergone stent implantation. Although coronary computed tomography angiography (CCTA) has been widely used for ISR assessing, stent narrow lumen and presence of stent's struts artifacts have limited its efficacy. The use of quantitative techniques may provide more valuable findings for ISR diagnosis. The aim of this study is to assess the predictive value of a quantitative technique of ISR estimation based on stent intraluminal enhancement derived from CCTA.Materials and Methods: In the current study, 40 patients with the previous history of coronary artery diseases (CADs) and coronary stent placement who reexperienced CAD symptoms and referred for CCTA were assessed in 2017-2018. Stent intraluminal "enhancement value" (EV) was measured using calcium score and post-contrast images of CCTA. The cutoff point was determined using conventional invasive coronary angiography as the gold standard.Results: Total numbers of 58 stents were evaluated, in which stent intraluminal enhancement was assessed in initial, middle, and end sites of stent, achieved cutoff points for more than 50% of ISR were 204, 168, and 204 Hounsfield units, respectively. These cutoff points had diagnostic value of 77.5% for initial part, 86% for midpart, and 81% for end part, respectively.Conclusion: The use of quantitative method of stent intraluminal EV for ISR estimation has better diagnostic value in comparison to qualitative techniques that can help better clinical decision making. Moreover, measurements of this method are somewhat easier and also secondary artifacts of stent struts and calcified plaques would be eliminated.